Recording and reproducing sound-waves



2 Sheets-Sheet 1.

(No Model.)

A. O. FERGUSON. RECORDING AND EEPRODUOING SOUND WAVES.

No. 539,254. Patented May 14, 1895.

q m/bneoiwo NlTE- STATES ARTHUR c. FERGUSON, or SARATOGA sPRInes, NEWYORK.

'ATENT- 'FFIGEQ RECORDING AND REPROD UCING SOUND-VVAVES.

SPECIFICATION forming part of Letters Patent No. 539,254, dated May 14,1895.

Application filed March 7, 1895- semi a. 540,844. (No model.)

ment'as will hereinafter be more particularly described.

The invention is adapted for the recording and reproduction ofarticulatespeech and all musical sounds alike, and it has for its object to provide a permanent record, as well as a more faithfulreproduction than has heretofore been accomplished.

The invention is distinguished from that class of devices wherein theoriginal impulses, or vibrations are photographically recorded andsubsequently reproduced either photographically or electrically, in thatthe sound waves are photographicallyrecorded and the reproduction orretransmission of the same is effected by mechanical means, therebyenabling me to both record and reproduce the sound Waves by the use ofbut one machine.

Generally speaking, the invention comprises photo-mechanical devices bywhich a beam of' light is projected ontoa rotating or movable film insinuous lines, the altitudes of which are in accordance with theamplitudes of the vibrations of the diaphragm, and the number orrecurrence of which lines are in accordance with the rates of suchvibrations.

In the accompanying drawings, Figure 1 is.

a view in perspective of a photomeohanical sound recording andreproducing device embodying the features of my invention. Fig. 2 is aside elevation, partly in section, representing the recording-needleinposition for operation and thereproducing-needle as turned to one side.Fig. 3 is a side view representing the recording-needle as thrown outofoperative position and the reproducing-needle in a position for use.

While my invention is capable of being constructed or carried intoefiect in a great many different ways, for the purpose of simplicitycross pieces 5 and 6.

and cheapness of cost, I provide a machine such as is indicated in theaccompanying drawings, wherein 1 designates a suitable base, and 2, 2,each indicates a standard or upright, one of which supports thetransmitter 3, and the other the receiver or reproducer .4, the saidstandards or uprights being connected in any suitable manner by means ofthe I As will be observed on reference to the several figures the saidtransmitting device is supported so as to be capable of being swung orturned on its support, andv while a great many constructions could beresorted to for this purpose, I preferably provide a plate or disk 7having an ofiset or projection 8' formed or provided Withan opening 9through which passes a screw 10 which enters or passes into an opening11 formed in the upper end of the standard or support 2. Thus byloosening the screw, I am enabled to turn the plate or disk in suchmanner as to carry the recording needle to one side substantially as isshown in Fig. 3 of the drawings. The said plate or disk 7 is also formedor provided with a small projectionor offset 12 through which isinserted from beneath an adjusting device or screw13, to the lower endof which ispivotally suspended the recording needle 14, the latterhaving at its outer end a small crook 15 having a rounded head 16 whichnormally bears very lightly against the under side of thediaphragm 17 ofthe said transmitting device 3; while to the opposite end of the saidrecording needle is attached in any suitable manner a shutter 18 of anysuitable thin opaque material, which shutter, as the recording needle iscaused to vibrate by the impulses imparted to the diaphragm, is in likemanner made to vibrate or move up and down in guides 19 formed on theouter side of a sheath or casing 20, the latter being provided with anopening 21 before which the movements of the shutter take place. Thesaid shutter is provided'with a Very fine opening 21, which, as isobvious, will cause a beam of light to be projected through the opening21 of the casing 'in sinuous lines whenever the said shutter is causedto move up and down by the action of the needle when receiving motionfrom the vibrations of the diaphragm. The said sheath or casing 20 isfor the purpose of closing over or surrounding a rotatingcylinder 25,and for the purpose of maintaining the casing stationary, the lower endof the latter is screw threaded at 26 to screw into or fit within acorrespondingly screw-threaded socket 27, preferablyin this instanceformed with or attached to the upper cross piece 5 which connects thestandards or uprights 2, 2. It is obvious that other means may beprovided for supporting the said sheathing or casing to inclose therotating cylinder but the means which I have shown and described arevery simple and amply suffice for the purpose.

In order to impart to the cylinder a rotating and gradually progressivemovement, I attach the same in any suitable way at its lower end to theupper end of a rotating shaft 42 formed on its lower portion with ascrew 29, and which screw threaded portion 'works in a screw bearing 30by which to effect a gradual feed of the cylinder in an upward directionas the said shaft is rotated either by hand or from any suitable motor,a driving pulley 32 being held on the shaft and provided with a feather,(not shown) working in a groove 35 in the shaft so as to permit of theproper movement of the latter.

Around the rotating cylinder 25 I place in any suitable manner asensitized photographic film 36, and then by properly inclosing the sameby the sheath or casing and swinging the shutter around and placing thesame within its guides on the casing, the machine is thus placed inreadiness to record sound waves produced by the vibrations of thediaphragm 17. By talking into the transmitter or producing musicalsounds therein, the diaphragm will vibrate, and the pulsations will beimparted to the recording needle which causes the shutter to move up anddown before the opening in the sheath or casing. During this time, themachine is in motion and the cylinder 25 with its film is caused torotate at the desired rate of speed, and the beam of light which passesthrough theopening in the shutter will be projected onto the surface ofthe film in sinuous lines in exact accordance with the amplitude ofvibrations of the diaphragm.

It is to be understood that the opening in the sheath or casing is ofsufficient dimensions to permit of recording the deepest sound wave ofwhich the diaphragm is capable of t remove the entire machine to aphotographic dark room and remove the sheath or casing, and then developthe sensitized film by the ordinary photographic process. As thusdeveloped, the said films can of course be kept as long as desired, butin order to reproduce the sound waves delineated thereon, I transfer thesinuous lines onto either a metal plate or cylinder, preferably in thisinstance a cylinder 40, and this cylinder is attached in any suitablemanner to the upper end of the shaft 42, whereupon the reproducingneedle is swung around in such manner as to engage the lines on thecylinder, and then as the cylinder is rotated an exact reproduction ofthe sound waves will be produced through the medium of the diaphragmcontained in the receiver 50. The construction of said re ceiver is inall important respects the same as the transmitter 3 with the exceptionthat a bracket 52 is employed additionally as a support for thereproducing needle 45, the latter being centrally supported at 46 andoperating at its outer end in connection with a fine rod 53 whichtransmits the sound waves on the cylinder to the diaphragm in thetransmitter.

It will be understood, of course, that the transfer of the sinuous linesfrom the film to the plate or cylinder may be either in intaglie orrelief and produce the same effect, and this transfer is effected eitherby etching or by any of the well known engraving or photoengravingprocesses, it being unnecessary to specifically set forth such processherein.

It is thought that from the foregoing description, the construction andoperation of my invention will be fully understood, and

while I have herein set forth certain preferred forms of construction ofthe several parts of my apparatus, it is evident that various immaterialchanges could be resorted to without departing from the principlesintended. For instance, I have herein stated that in order to developthe film after its surface has been completely utilized, the entiremachine is removed to the dark room, whereas it is clearly evident thatby slightly altering the construction of the machine, the removal of thefilm alone together with its surrounding sheath could be independentlyeffected. In connection also with both the recording and reproducingneedles, it will be understood that their construction and arrangementis capable of various modifications. For all practical purposes however,I have found the present construction to answer, and therefore Ipreferably resort thereto in the practice of my invention.

Without limiting myself to the precise construction and arrangement ofparts shown, I claim as my invention- 1. In means for recording andreproducing sound waves, a gradually progressive rotating sensitizedfilm, a sheath or casing inclosing the same and provided with anopening, a shutter of opaque material arranged before said opening andperforated, a receiver pro-.

vided with a diaphragm, and a recording needle operated by thevibrations of said diaphragm and imparting corresponding vibrations tosaid shutter, substantially as shown and for the purpose described.

2. In means for recording and reproducing sound waves, a receiving orrecording diaphragm supported so as to swing to one side, a recordingneedle pivoted to the frame of said diaphragm with one end bearinglightly on the latter, a shutter carried by the opposite end of saidneedle, the rotating'cylinder adapted to receive the film, means forrotating the said cylinder and gradually feeding the same, and a sheathor casing inclosing the cylinder provided with an opening before whichthe shutter is operated by impulses from the diaphragm, substantially asdescribed.

3. In means for recording and reproducing sound waves, the combinationof the rotating screw shaft adapted to support a cylinder, the receivingand reproducing diaphragms, the recording and reproducing needles, andmeans whereby either one or both of said needles may be swung to oneside, substantially as shown and for the purpose set forth.

4. In means for recording and reproducing sound waves, a graduallyrotating sensitized film, an inclosure therefor provided with anopening, a shutter perforated and located before said opening, areceiving diaphragm, and devices intermediate of said diaphragm andshutter whereby the latter is operated in ac cordancewith thevibrationsof thediaphragm, substantially as shown and for the purpose set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ARTHUR C. FERGUSON.

Witnesses:

E. EVERETT ELLIS, JNo. G. I-IINKEL.

